Process of making web or fiberfill from polytrimethylene terephthalate staple fibers

Abstract

The invention relates to webs or batts including polytrimethylene terephthalate crimped staple fibers and fiberfill products comprising such webs and batts, as well as the processes of making the staple fibers, webs, batts and fiberfill products. According to the preferred process of making a web or batt, polytrimethylene terephthalate staple fibers, containing polytrimethylene terephthalate is melt spun at a temperature of 245-285° C. into filaments. The filaments are quenched, drawn and mechanically crimped to a crimp level of 8-30 crimps per inch (3-12 crimps/cm). The crimped filaments are relaxed at a temperature of 50-130° C. and then cut into staple fibers having a length of about 0.2-6 inches (about 0.5-about 15 cm). A web is formed by garnetting or carding the staple fibers and is optionally cross-lapped to form a batt. A fiberfill product is prepared with the web or batt.

1. A process of making a web or batt comprising polytrimethylene terephthalate staple fibers, comprising (a) providing polytrimethylene terephthalate, (b) melt spinning the melted polytrimethylene terephthalate at a temperature of 245-285° C. into filaments, (c) quenching the filaments, (d) drawing the quenched filaments, (e) crimping the drawn filaments using a mechanical crimper at a crimp level of 8-30 crimps per inch, (f) relaxing the crimped filaments at a temperature of 50-130° C., (g) cutting the relaxed filaments into staple fibers having a length of about 0.2-6 inches, (h) garnetting or carding the staple fibers to form a web and (i) optionally cross-lapping the web to form a batt. 
     
     
       2. The process of  claim 1  wherein the staple fibers have a denier of3 to 15. 
     
     
       3. The process of  claim 2  wherein the staple fibers have a length of about 0.5-about 3 inches. 
     
     
       4. The process of  claim 1  wherein the staple fibers have a crimp take-up of 30% or more. 
     
     
       5. The process of  claim 3  wherein the staple fibers have a crimp take-up of 30% or more. 
     
     
       6. The process of  claim 1  wherein the relaxation is at 105° C. or less. 
     
     
       7. The process of  claim 1  further comprising bonding the web. 
     
     
       8. The process of  claim 7  wherein the bonding is selected from the group consisting of spray bonding, thermal bonding and ultrasonic bonding. 
     
     
       9. The process of  claim 8  wherein a low bonding temperature staple fiber is mixed with the staple fibers to enhance bonding. 
     
     
       10. The process of  claim 1  wherein fibers selected from the group consisting of cotton, polyethylene terephthalate, nylon, acrylate and polybutylene terephthalate fibers are mixed with the staple fibers. 
     
     
       11. The process of  claim 1  wherein the relaxation is carried out by heating the crimped filaments in an unconstrained condition. 
     
     
       12. The process of  claim 2  wherein the staple fibers are 3-9 denier per filament. 
     
     
       13. The process of  claim 1  which is carried out without an anneal step after drawing and before crimping and relaxing. 
     
     
       14. A process of making a fiberfill product comprising polytrimethylene terephthalate staple fibers, comprising (a) providing polytrimethylene terephthalate, (b) melt spinning the melted polytrimethylene terephthalate at a temperature of 245-285° C. into filaments, (c) quenching the filaments, (d) drawing the quenched filaments, (e) crimping the drawn filaments using a mechanical crimper at a crimp level of 8-30 crimps per inch, (f) relaxing the crimped filaments at a temperature of 50-130° C., (g) cutting the relaxed filaments into staple fibers having a length of about 0.2-6 inches, (h) garnetting or carding the staple fibers to form a web, (i) optionally cross-lapping the web to form a batt, and (j) filling the web or batt into a fiberfill product. 
     
     
       15. The process of  claim 14  wherein the staple fibers have a denier of 3 to 15 and a length of about 0.5-about 3 inches. 
     
     
       16. The process of  claim 14  wherein the cross-lapping is carried out. 
     
     
       17. The process of  claim 16  further comprising bonding the web. 
     
     
       18. The process of  claim 14  wherein the relaxation is at 105° C. or less. 
     
     
       19. The process of  claim 14  wherein fibers selected from the group consisting of cotton, polyethylene terephthalate, nylon, acrylate and polybutylene terephthalate fibers are mixed with the staple fibers. 
     
     
       20. The process of  claim 1  wherein the relaxation is at less than 100° C. 
     
     
       21. The process of  claim 20  wherein the relaxation is at less than 80° C. 
     
     
       22. The process of  claim 20  wherein the relaxation is at 60° C. or above and the relaxation comprises passing the filaments through an oven at a rate of 50-200 yards/minute for 6-20 minutes. 
     
     
       23. The process of  claim 20  which is carried out without an anneal step after drawing and before crimping and relaxing. 
     
     
       24. The process of  claim 1  wherein the drawing is carried out using two-stage drawing. 
     
     
       25. The process of  claim 24  wherein the two stage drawing comprises (a) a first stage drawing at room temperature and (b) the remaining drawing with the fiber immersed in atmospheric steam set to 90-100° C. 
     
     
       26. The process of  claim 25  wherein 80-90% of the total draw is done in the first stage and 10-20% of the drawing is done in the remaining drawing. 
     
     
       27. The process of  claim 25  wherein the two stage drawing comprises (a) a first stage drawing at room temperature and (b) the remaining drawing with the fiber immersed in a heated water spray. 
     
     
       28. The process of  claim 25  wherein the two stage drawing comprises (a) a first stage drawing at room temperature and (b) the remaining drawing with the fiber immersed in a heated water spray. 
     
     
       29. The process of  claim 1  wherein the drawing is carried out using single-stage drawing. 
     
     
       30. The process of  claim 29  wherein tension and a water spray are applied to the drawn filament after drawing. 
     
     
       31. The process of  claim 24  wherein the drawing is carried out using a draw ratio of about 1.25-about 4. 
     
     
       32. The process of  claim 28  wherein the drawing is carried out using a draw ratio of about 1.25-about 4. 
     
     
       33. The process of  claim 28  wherein the relaxation is at less than 100° C. 
     
     
       34. The process of  claim 33  which is carried out without an anneal step after drawing and before crimping and relaxing. 
     
     
       35. The process of  claim 14  wherein the relaxation is at 60° C. to less than 100° C. and the relaxation comprises passing the filaments through an oven at a rate of 50-200 yards/minute for 6-20 minutes. 
     
     
       36. The process of  claim 14  wherein the relaxation is at less than 80° C. 
     
     
       37. The process of  claim 14  which is carried out without an anneal step after drawing and before crimping and relaxing. 
     
     
       38. The process of  claim 36  which is carried out without an anneal step after drawing and before crimping relaxing. 
     
     
       39. The process of  claim 38  wherein the drawing is carried out using two-stage drawing comprising (a) a first stage drawing at room temperature and (b) the remaining drawing with the fiber immersed in atmospheric steam set to 90-100° C.; wherein 80-90% of the total draw is done in the first stage and 10-20% of the drawing is done in the remaining drawing; wherein the drawing is carried out using a draw ratio of about 1.25-about 4; wherein the relaxation is at 60° C. or above and comprises passing the filaments through an oven at a rate of 50-200 yards/minute for 6-20 minutes. 
     
     
       40. The process of  claim 38  wherein the drawing is carried out using two-stage drawing comprising (a) a first stage drawing at room temperature and (b) the remaining drawing with the fiber immersed in a heated water spray, and wherein the drawing is carried out using a draw ratio of about 1.25-about 4. 
     
     
       41. The process of  claim 38  wherein the drawing is carried out using single-stage drawing, wherein tension and a water spray are applied to the drawn filament after drawing, and wherein the drawing is carried out using a draw ratio of about 1.25-about 4.